Development of Surface EMG for Gait Analysis and Rehabilitation of Hemiparetic Patients.

BACKGROUND: The quantification of electromyographic activity using surface electrodes is invaluable for understanding gait disorders in patients with central nervous system lesions. We propose to evaluate a commercially available low-cost system compared to a reference system in participants with stroke-related movement disorders in functional situations. METHODS: Three hemiparetic participants performed three functional tasks: two treadmill walks at different speeds and a sit-to-stand test. The vastus lateralis and gastrocnemius medialis muscles were equipped with two EMG sensors. The comparison between the two EMG systems was based on 883 identified cycles. Spearman's correlation coefficients (SCs), linear correlation coefficients (LCCs), and cross-correlation coefficients (CCCs) were calculated. RESULTS: The main results indicate good to very good similarity of the EMG signals collected from the two tested sEMG systems. In the comfortable-walking condition, an SC of 0.894 ± 0.091 and an LCC of 0.909 ± 0.094 were noted. In the fast-walking condition, an SC of 0.918 ± 0.064 and an LCC of 0.935 ± 0.056 were observed. For the 1 min sit-to-stand test, an SC of 0.880 ± 0.058 and an LCC of 0.881 ± 0.065 were noted. CONCLUSIONS: This study demonstrates good to very good similarity between the two sEMG systems, enabling the analysis of muscle activity during functional tasks.

Armeo®Spring therapy improves movement efficiency and contributes to a better quality of life.

OBJECTIVES: The main objective was to explore the effect of exoskeleton-assisted rehabilitation on quality of life in the subacute state of ischemic stroke. BACKGROUND: Central upper extremity hemiparesis affects self-care, social participation, and quality of life. Exoskeleton devices serve as a therapeutic tool and an assessment tool that offers precise tracking of patient progress and evaluation of impairment. METHODS: The trial was carried out from April 2022 to September 2023. Twenty-seven patients were randomly assigned to the intervention (14 participants; mean age 64.71 years; 5 women, 9 men) and control group (13 participants; mean age 64.69 years; 6 women, 7 men). Both groups received equal total therapy (10 to 12 sessions, 5 times a week). The intervention group received 30 minutes of Armea®Spring training combined with conventional rehabilitation. The control group was subjected to conventional rehabilitation. RESULTS: In the comparison between groups, the experimental group achieved significant changes in quality of life, movement efficiency, and functional performance of the upper extremities. CONCLUSIONS: Armeo®Spring therapy combined with usual care led to significantly larger changes in health-related quality of life and upper extremity movement efficiency compared to conventional rehabilitation (Tab. 4, Fig. 3, Ref. 64.) Text in PDF www.elis.sk Keywords: stroke, hemiparesis, health-related quality of life, Armeo®Spring, movement efficiency, activities of daily living.

Explicit and implicit locomotor learning in individuals with chronic hemiparetic stroke.

Motor learning involves both explicit and implicit processes that are fundamental for acquiring and adapting complex motor skills. However, stroke may damage the neural substrates underlying explicit and/or implicit learning, leading to deficits in overall motor performance. Although both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke when tested during a task that elicits dissociable contributions from both. Here, we compared explicit and implicit locomotor learning in individuals with chronic stroke to age- and sex-matched neurologically intact controls. We assessed implicit learning using split-belt adaptation (where two treadmill belts move at different speeds). We assessed explicit learning (i.e., strategy-use) using visual feedback during split-belt walking to help individuals explicitly correct for step length errors created by the split-belts. After the first 40 strides of split-belt walking, we removed the visual feedback and instructed individuals to walk comfortably, a manipulation intended to minimize contributions from explicit learning. We used a multirate state-space model to characterize individual explicit and implicit process contributions to overall behavioral change. The computational and behavioral analyses revealed that, compared with controls, individuals with chronic stroke demonstrated deficits in both explicit and implicit contributions to locomotor learning, a result that runs counter to prior work testing each process individually during gait. Since poststroke locomotor rehabilitation involves interventions that rely on both explicit and implicit motor learning, future work should determine how locomotor rehabilitation interventions can be structured to optimize overall motor learning. NEW & NOTEWORTHY Motor learning involves both implicit and explicit processes, the underlying neural substrates of which could be damaged after stroke. Although both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke. Using a locomotor task that elicits dissociable contributions from both processes and computational modeling, we found evidence that chronic stroke causes deficits in both explicit and implicit locomotor learning.

Effect of touch screen tablet use on fine motor functions in children with hemiparetic cerebral palsy: A randomized controlled trial.

BACKGROUND: Cerebral palsy is the most frequent condition affecting the central nervous system and causing large disability. OBJECTIVE: To determine the impact of touch screen tablet upon fine motor functions in children with hemiparesis. METHOD: This was a randomized controlled trial involving 60 children, ranging in age from 5 to 7 years old, randomized into two groups: intervention or control group (30 children per group). Both groups were given 12 consecutive weeks of designed fine motor tasks. Additionally, for thirty minutes, the intervention group was given a fine motor exercise program on a touch screen tablet. Upper limb function, finger dexterity and pinch strength were measured pre and post the recommended treatment program using the quality of upper extremity skill test (QUEST), Nine-Hole Peg Test and Jamar hydraulic pinch gauge, respectively. RESULTS: All outcome measures were equivalent between intervention groups at admission (P > 0.05). Significant improvements were found in all assessed variables within the two groups. Meanwhile, the intervention group had significantly higher improvements (P < 0.05) in finger dexterity, pinch strength, and upper limb function when compared with the control groups. CONCLUSION: Including a touch screen smart tablet application with a specially designed fine motor program is an effective method that helps children with U-CP perform more effectively with their fine motor skills.

The Kinematics of 3D Arm Movements in Sub-Acute Stroke: Impaired Inter-Joint Coordination is Attributable to Both Weakness and Flexor Synergy Intrusion.

BACKGROUND: It has long been of interest to characterize the components of the motor abnormality in the arm after stroke. One approach has been to decompose the hemiparesis phenotype into negative signs, such as weakness, and positive signs, such as intrusion of synergies. We sought to identify the contributions of weakness and flexor synergy to motor deficits in sub-acute stroke. METHODS: Thirty-three sub-acute post-stroke participants and 16 healthy controls performed two functional arm movements; one within flexor synergy (shoulder and elbow flexion), and the other outside flexor synergy (shoulder flexion and elbow extension). We analyzed upper limb 3D kinematics to assess both overall task performance and intrusion of pathological synergies. Weakness and spasticity were also measured. RESULTS: Both tasks produced similar impairments compared to controls. Analysis of elbow and shoulder multi-joint coordination patterns revealed intrusion of synergies in the out-of-synergy reaching task based on the time spent within a flexion-flexion pattern and the correlation between shoulder and elbow angles. Regression analysis indicated that both weakness and synergy intrusion contributed to motor impairment in the out-of-synergy reaching task. Notably, the Fugl-Meyer Assessment (FMA) was abnormal even when only weakness caused the impairment, cautioning that it is not a pure synergy scale. CONCLUSIONS: Weakness and synergy intrusion contribute to motor deficits in the sub-acute post-stroke period. An abnormal FMA score cannot be assumed to be due to synergy intrusion. Careful kinematic analysis of naturalistic movements is required to better characterize the contribution of negative and positive signs to upper limb impairment after stroke.

Motor interference on lateral pelvis shifting towards the paretic leg during walking and its cortical mechanisms in persons with stroke.

Motor interference, where new skill acquisition disrupts the performance of a previously learned skill, is a critical yet underexplored factor in gait rehabilitation post-stroke. This study investigates the interference effects of two different practice schedules, applying interleaved (ABA condition) and intermittent (A-A condition) pulling force to the pelvis during treadmill walking, on lateral pelvis shifting towards the paretic leg in individuals with stroke. Task A involved applying resistive pelvis force (pulling towards the non-paretic side), and Task B applied assistive force (pulling towards the paretic side) at the stance phase of the paretic leg during walking. Sixteen individuals with chronic stroke were tested for gait pattern changes, including lateral pelvis shifting and spatiotemporal gait parameters, and neurophysiological changes, including muscle activity in the paretic leg and beta band absolute power in the lesioned cortical areas. A-A condition demonstrated increased lateral pelvis shifting towards the paretic side, extended paretic stance time and longer non-paretic step length after force release while ABA condition did not show any changes. These changes in gait pattern after A-A condition were accompanied by increased muscle activities of the ankle plantarflexors, and hip adductors/abductors. A-A condition demonstrated greater changes in beta band power in the sensorimotor regions compared to ABA condition. These findings suggest that while walking practice with external force to the pelvis can improve lateral pelvis shifting towards the paretic leg post-stroke, practicing a new pelvis shifting task in close succession may hinder the performance of a previously obtained lateral pelvis shifting pattern during walking.

Cautious Gait during Navigational Tasks in People with Hemiparesis: An Observational Study.

Locomotor and balance disorders are major limitations for subjects with hemiparesis. The Timed Up and Go (TUG) test is a complex navigational task involving oriented walking and obstacle circumvention. We hypothesized that subjects with hemiparesis adopt a cautious gait during complex locomotor tasks. The primary aim was to compare spatio-temporal gait parameters, indicators of cautious gait, between the locomotor subtasks of the TUG (Go, Turn, Return) and a Straight-line walk in people with hemiparesis. Our secondary aim was to analyze the relationships between TUG performance and balance measures, compare spatio-temporal gait parameters between fallers and non-fallers, and identify the biomechanical determinants of TUG performance. Biomechanical parameters during the TUG and Straight-line walk were analyzed using a motion capture system. A repeated measures ANOVA and two stepwise ascending multiple regressions (with performance variables and biomechanical variables) were conducted. Gait speed, step length, and % single support phase (SSP) of the 29 participants were reduced during Turn compared to Go and Return and the Straight-line walk, and step width and % double support phase were increased. TUG performance was related to several balance measures. Turn performance (R2 = 63%) and Turn trajectory deviation followed by % SSP on the paretic side and the vertical center of mass velocity during Go (R2 = 71%) determined TUG performance time. People with hemiparesis adopt a cautious gait during complex navigation at the expense of performance.

Validity and reliability of the chronic composite XA, an upper limb motor assessment using Active Range of Motion in patients with chronic stroke.

BACKGROUND: Upper limb (UL) spastic paresis has been classically evaluated with assessments of passive movements with limited functional validity. The aim of this study was to assess whether a composite measure of active range of motion (AROM, or XA) is valid and reliable in chronic post-stroke spastic paresis. AIM: The primary objective was to investigate the validity and reliability of a composite score, comprising multiple XA measurements, to assess UL spastic paresis in patients in chronic stages post-stroke. In addition to this, an exploratory analysis was conducted to identify which muscles should be optimally included in this composite score. DESIGN: A psychometric proprieties study. SETTING: Physical and Rehabilitation Medicine Department. POPULATION: twenty-eight chronic post-stroke participants with spastic paresis. METHODS: Composite UL XA measurement in twenty-eight chronic post-stroke participants (age=59±11 years; delay post-stroke=29±37 months) with spastic paresis was repeated twice about 40 days apart in a standardized body position. Concurrent and construct validity was evaluated exploring correlation with the Fugl-Meyer Assessment Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), and grip strength (JAMAR™). Reliability was assessed by calculating intraclass correlation coefficients (ICC). Regarding the exploratory analysis, a linear regression analysis was performed to examine the value of including various muscles. RESULTS: Composite XA against the resistance of elbow, wrist and finger flexors showed strong correlation with FMA-UE and ARAT (r=0.88; P<0.001 and r=0.82; P<0.001 respectively) and a weak association with grip strength (r=0.43; P=0.03). Test-retest reliability was excellent (ICC=0.92). However, the most effective regression model also included XA against the resistance of shoulder adductors as well as forearm pronator (adjusted R2=0.85; AIC=170). CONCLUSIONS: The present study provided satisfactory psychometric data for the upper limb composite active movement (CXA), derived from the Five Step Assessment. For overall measurement of UL mobility after stroke, we strongly recommend including shoulder and forearm muscles to the score. CLINICAL REHABILITATION IMPACT: Composite XA is a valid and reliable measure of upper limb motor function in chronic post-stroke patients and could be used in clinical practice and research.

Olfactory Dysfunction as a Marker for Cognitive Impairment in General Paresis of the Insane: A Clinical Study.

BACKGROUND General paresis of the insane (GPI) is characterized by cognitive impairment, neuropsychiatric symptoms, and brain structural abnormalities, mimicking many neuropsychiatric diseases. Olfactory dysfunction has been linked to cognitive decline and neuropsychiatric symptoms in numerous neuropsychiatric diseases. Nevertheless, it remains unclear whether patients with GPI experience olfactory dysfunction and whether olfactory dysfunction is associated with their clinical manifestations. MATERIAL AND METHODS Forty patients with GPI and 37 healthy controls (HCs) underwent the "Sniffin Sticks" test battery, Mini-Mental State Examination, and Neuropsychiatric Inventory to measure olfactory function, cognitive function, and neuropsychiatric symptoms, respectively. Brain structural abnormalities were evaluated using visual assessment scales including the medial temporal lobe atrophy (MTA) visual rating scale and Fazekas scale. RESULTS Compared with HCs, patients with GPI exhibited significant olfactory dysfunction, as indicated by deficits in the odor threshold (OT) (P=0.001), odor discrimination (OD) (P<0.001), and odor identification (OI) (P<0.001). In patients with GPI, the OI was positively correlated with cognitive function (r=0.57, P<0.001), but no significant correlation was found between olfactory function and neuropsychiatric symptoms, blood, or cerebrospinal fluid biomarkers (rapid plasma reagin circle card test and Treponema pallidum particle agglutination test), or brain structural abnormalities (MTA and Fazekas scale scores). Mediation analysis indicated that the impaired OI in patients with GPI was mediated by cognitive impairment and impaired OT respectively. CONCLUSIONS Patients with GPI exhibited overall olfactory dysfunction. OI is correlated with cognitive function and the impaired OI is mediated by cognitive impairment in patients with GPI. Thus, OI may serve as a marker for reflecting cognitive function in patients with GPI.

Alterations of tactile and anatomical spatial representations of the hand after stroke.

Stroke often causes long-term motor and somatosensory impairments. Motor planning and tactile perception rely on spatial body representations. However, the link between altered spatial body representations, motor deficit and tactile spatial coding remains unclear. This study investigates the relationship between motor deficits and alterations of anatomical (body) and tactile spatial representations of the hand in 20 post-stroke patients with upper limb hemiparesis. Anatomical and tactile spatial representations were assessed from 10 targets (nails and knuckles) respectively cued verbally by their anatomical name or using tactile stimulations. Two distance metrics (hand width and finger length) and two structural measures (relative organization of targets positions and angular deviation of fingers from their physical posture) were computed and compared to clinical assessments, normative data and lesions sites. Over half of the patients had altered anatomical and/or tactile spatial representations. Metrics of tactile and anatomical representations showed common variations, where a wider hand representation was linked to more severe motor deficits. In contrast, alterations in structural measures were not concomitantly observed in tactile and anatomical representations and did not correlate with clinical assessments. Finally, a preliminary analysis showed that specific alterations in tactile structural measures were associated with dorsolateral prefrontal stroke lesions. This study reveals shared and distinct characteristics of anatomical and tactile hand spatial representations, reflecting different mechanisms that can be affected differently after stroke: metrics and location of tactile and anatomical representations were partially shared while the structural measures of tactile and anatomical representations had distinct characteristics.

Antagonist Activation Measurement in Triceps Surae Using High-Density and Bipolar Surface EMG in Chronic Hemiparesis.

After a stroke, antagonist muscle activation during agonist command impedes movement. This study compared measurements of antagonist muscle activation using surface bipolar EMG in the gastrocnemius medialis (GM) and high-density (HD) EMG in the GM and soleus (SO) during isometric submaximal and maximal dorsiflexion efforts, with knee flexed and extended, in 12 subjects with chronic hemiparesis. The coefficients of antagonist activation (CAN) of GM and SO were calculated according to the ratio of the RMS amplitude during dorsiflexion effort to the maximal agonist effort for the same muscle. Bipolar CAN (BipCAN) was compared to CAN from channel-specific (CsCAN) and overall (OvCAN) normalizations of HD-EMG. The location of the CAN centroid was explored in GM, and CAN was compared between the medial and lateral portions of SO. Between-EMG system differences in GM were observed in maximal efforts only, between BipCAN and CsCAN with lower values in BipCAN (p < 0.001), and between BipCAN and OvCAN with lower values in OvCAN (p < 0.05). The CAN centroid is located mid-height and medially in GM, while the CAN was similar in medial and lateral SO. In chronic hemiparesis, the estimates of GM hyperactivity differ between bipolar and HD-EMGs, with channel-specific and overall normalizations yielding, respectively, higher and lower CAN values than bipolar EMG. HD-EMG would be the way to develop personalized rehabilitation programs based on individual antagonist activations.

Defining pseudoparalysis and pseudoparesis: a consensus study.

BACKGROUND: The purpose of this study was to establish consensus statements via a modified Delphi process on the definition of shoulder pseudoparalysis and pseudoparesis. METHODS: A consensus process on the definition of a diagnosis of pseudoparalysis utilizing a modified Delphi technique was conducted, and 26 shoulder/sports surgeons from 11 countries, selected based on their level of expertise in the field, participated in these consensus statements. Consensus was defined as achieving 80%-89% agreement, whereas strong consensus was defined as 90%-99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: Three statements regarding the diagnosis of pseudoparalysis reached strong (>89%) consensus: passive range of motion should be unaffected, the passive range of abduction should not be considered, and diagnosis should be excluded if lidocaine injection produces a substantial improvement in range of motion. Additionally, consensus (>79%) was reached that the active range of external rotation should not be considered for diagnosis, pain as a cause of restricted motion must be excluded, and that distinctions between restricted active flexion and external rotation should be made by range of motion rather than tear characteristics. No consensus could be reached on statements regarding the size, number of tendons or chronicity of cuff tears. Nor was there agreement on the active range of flexion permitted or on the difference between pseudoparalysis and pseudoparesis. CONCLUSION: A modified Delphi process was utilized to establish consensus on the definition of shoulder pseudoparalysis and pseudoparesis. Unfortunately, almost half of the statements did not reach consensus, and agreement could not be reached across all domains for a unifying definition for the diagnosis of pseudoparalysis in the setting of rotator cuff tears. Furthermore, it was not agreed how or whether pseudoparalysis should be differentiated from pseudoparesis. Based on the lack of a consensus for these terms, studies should report explicitly how these terms are defined when they are used.

Radiomic white matter parameters of functional integrity of the corticospinal tract in high-grade glioma.

Tractography has become a widely available tool for the planning of neurosurgical operations as well as for neuroscientific research. The absence of patient interaction makes it easily applicable. However, it leaves uncertainty about the functional relevance of the identified bundles. We retrospectively analyzed the correlation of white matter markers with their clinical function in 24 right-handed patients who underwent first surgery for high-grade glioma. Morphological affection of the corticospinal tract (CST) and grade of paresis were assessed before surgery. Tractography was performed manually with MRTrix3 and automatically with TractSeg. Median and mean fractional anisotropy (FA) from manual tractography showed a significant correlation with CST affection (p = 0.008) and paresis (p = 0.015, p = 0.026). CST affection correlated further most with energy, and surface-volume ratio (p = 0.014) from radiomic analysis. Paresis correlated most with maximum 2D column diameter (p = 0.005), minor axis length (p = 0.006), and kurtosis (p = 0.008) from radiomic analysis. Streamline count yielded no significant correlations. In conclusion, mean or median FA can be used for the assessment of CST integrity in high-grade glioma. Also, several radiomic parameters are suited to describe tract integrity and may be used to quantitatively analyze white matter in the future.

Impact of plantar flexion resistive moment of dynamic ankle foot orthosis on measures of center of pressure and clinical gait outcomes in individuals with post-stroke hemiparesis.

BACKGROUND: An ankle-foot orthosis (AFO) with plantar flexion resistance (PFR) can improve the first rocker function during gait, but the incremental changes in the resistive moment on balance and gait have not been well identified. OBJECTIVES: To investigate the effect of changing the PFR moment of dynamic AFO (DAFO) on measures of the center of pressure (COP) and clinical gait outcomes in individuals with post-stroke hemiparesis. METHOD: In this randomized repeated measure study of 36 stroke individuals, the customized DAFO using foot drop ankle units set in three PFR situations (low, medium, and high) was evaluated. The balance parameters for COP measures were investigated by HUMAC® Balance & Tilt System. Gait parameters and ankle kinematics were recorded using the 3D motion analysis through force platform and optoelectronic system. The comparison was made using a parametric ANOVA test and the P value was set at 0.05 for statistical significance. RESULTS: Significant differences were observed for COP average velocity (1.30 ± 0.64, 1.10 ± 0.05, and 1.37 ± 0.43), COP path length (43.3 ± 4.6, 33.4 ± 4.3, and 36.3 ± 5.4), walking velocity (11.0 ± 3.1, 13.2 ± 4.4, and 9.9 ± 3.5), and cadence (31.5 ± 2.0, 33.0 ± 3.1, and 29.0 ± 1.6) respectively for low, medium and high PFR settings (P < 0.05). Except for the COP path length and cadence, posthoc multiple comparisons revealed significant differences between low and medium (P < 0.05) and medium and high (P < 0.05) PFR grades. PFR with medium resistance demonstrated near-normal maximal peak ankle dorsiflexion (mean deviation of 8 degrees, P < 0.05). CONCLUSION: Medium PFR grade should be encouraged since it can enhance balance parameters like path length and average velocity of COP, increase cadence and average velocity during gait, and improve maximal peak ankle dorsiflexion.

Sensory Stimulation and Robot-Assisted Arm Training After Stroke: A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Functional recovery after stroke is often limited, despite various treatment methods such as robot-assisted therapy. Repetitive sensory stimulation (RSS) might be a promising add-on therapy that is thought to directly drive plasticity processes. First positive effects on sensorimotor function have been shown. However, clinical studies are scarce, and the effect of RSS combined with robot-assisted training has not been evaluated yet. Therefore, our objective was to investigate the feasibility and sensorimotor effects of RSS (compared to a control group receiving sham stimulation) followed by robot-assisted arm therapy. METHODS: Forty participants in the subacute phase (4.4-23.9 weeks) after stroke with a moderate to severe arm paresis were randomized to RSS or control group. Participants received 12 sessions of (sham-) stimulation within 3 weeks. Stimulation of the fingertips and the robot-assisted therapy were each applied in 45-min sessions. Motor and sensory outcome assessments (e.g. Fugl-Meyer-Assessment, grip strength) were measured at baseline, post intervention and at a 3-week follow-up. RESULTS: Participants in both groups improved their sensorimotor function from baseline to post and follow-up measurements, as illustrated by most motor and sensory outcome assessments. However, no significant group effects were found for any measures at any time ( P > 0.058). Stimulations were well accepted, no safety issues arose. DISCUSSION AND CONCLUSIONS: Feasibility of robot-assisted therapy with preceding RSS in persons with moderate to severe paresis was demonstrated. However, RSS preceding robot-assisted training failed to show a preliminary effect compared to the control intervention. Participants might have been too severely affected to identify changes driven by the RSS, or these might have been diluted or more difficult to identify because of the additional robotic training and neurorehabilitation. VIDEO ABSTRACT AVAILABLE: for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A478 ).

Categorizing knee hyperextension patterns in hemiparetic gait and examining associated impairments in patients with chronic stroke.

BACKGROUND: Post-stroke hemiparetic gait exhibits considerable variations in motion patterns and abnormal muscle activities, notably knee hyperextension during the stance phase. Existing studies have primarily concentrated on its joint angle or moment. However, the underlying causes remain unclear. Thus, the causes of knee hyperextension were explored from a new perspective based on temporal-durational factors. RESEARCH QUESTION: Does the temporal-durational difference of knee hyperextension presence result from specific decreased motor functions? METHODS: Barefoot gait at a comfortable speed was captured using a three-dimensional camera system. Scores of knee hyperextension used a metric with the temporal-durational factor of knee hyperextension presence in each of four stance phases (1st double support, DS1; early single-leg stance, ESS; late single-leg stance, LSS; 2nd double support, DS2). These scores were used in cluster analysis. The classification and regression tree analysis characterizing each knee hyperextension cluster used the clinical measures of the lower limb and trunk motor function, muscle strength, and spasticity as explanatory variables. RESULTS: Thirty patients with hemiparetic chronic stroke who exhibited knee hyperextension during gait were included. Four knee hyperextension clusters were shown: Momentary (almost no hyperextension), Continuous (DS1-DS2), ESS-LSS, and ESS-DS2. Knee flexor strength was lower in the groups with long hyperextension durations (Continuous and ESS-DS2) compared with short durations (ESS-LSS and Momentary). ESS-DS2 exhibited higher trunk motor function than Continuous, whereas more severe spasticity was observed in ESS-LSS than in Momentary. SIGNIFICANCE: This study successfully classified four hemiparetic gait patterns with knee hyperextension based on the temporal-durational factor, providing valuable perspectives for understanding and addressing specific functional physical impairments. These findings offer guidance for focusing on related physical functions when striving for gait improvement with knee hyperextension and are expected to serve as a reference for treatment decision-making.

Clinical validation of automated depth camera-based measurement of the Fugl-Meyer assessment for upper extremity.

OBJECTIVE: Depth camera-based measurement has demonstrated efficacy in automated assessment of upper limb Fugl-Meyer Assessment for paralysis rehabilitation. However, there is a lack of adequately sized studies to provide clinical support. Thus, we developed an automated system utilizing depth camera and machine learning, and assessed its feasibility and validity in a clinical setting. DESIGN: Validation and feasibility study of a measurement instrument based on single cross-sectional data. SETTING: Rehabilitation unit in a general hospital. PARTICIPANTS: Ninety-five patients with hemiparesis admitted for inpatient rehabilitation unit (2021-2023). MAIN MEASURES: Scores for each item, excluding those related to reflexes, were computed utilizing machine learning models trained on participant videos and readouts from force test devices, while the remaining reflex scores were derived through regression algorithms. Concurrent criterion validity was evaluated using sensitivity, specificity, percent agreement and Cohen's Kappa coefficient for ordinal scores of individual items, as well as correlations and intraclass correlation coefficients for total scores. Video-based manual assessment was also conducted and compared to the automated tools. RESULT: The majority of patients completed the assessment without therapist intervention. The automated scoring models demonstrated superior validity compared to video-based manual assessment across most items. The total scores derived from the automated assessment exhibited a high coefficient of 0.960. However, the validity of force test items utilizing force sensing resistors was relatively low. CONCLUSION: The integration of depth camera technology and machine learning models for automated Fugl-Meyer Assessment demonstrated acceptable validity and feasibility, suggesting its potential as a valuable tool in rehabilitation assessment.

Correlations in abnormal synergies between the upper and lower extremities across various phases of stroke.

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and the lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However, less attention has been paid to the interlimb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke. We used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis after stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy after stroke. We found that, generally, strong interlimb correlations (r > 0.65 with all P values < 0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). However, the correlations of the lower-extremity extension synergy with the upper-extremity flexion synergy and extension synergy decreased (down to r = 0.38) 360 days after stroke (P < 0.05). These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances the interlimb correlations between the flexion synergy and extension synergy. At the same time, the results imply that the recovery of CST integrity or/and the fragmentation (remodeling) of the alternative neural substrates in the chronic phase may contribute to diversity in neural pathways in motor execution, eventually leading to reduced interlimb correlations.NEW & NOTEWORTHY For the first time, this article addresses the asynchronous relationships in the strengths of flexion and extension synergy expressions between the paretic upper extremity and lower extremity across various phases of stroke.

Effects of ankle-foot orthosis with dorsiflexion resistance on the quasi-joint stiffness of the ankle joint and spatial asymmetry during gait in patients with hemiparesis.

BACKGROUND: Reduced ankle quasi-joint stiffness affects propulsion in the paretic side of patients with hemiparesis, contributing to gait asymmetry. We investigated whether the use of an ankle-foot orthosis with dorsiflexion resistance to compensate for reduced stiffness would increase quasi-joint stiffness and spatiotemporal symmetry in patients with hemiparesis. METHODS: Seventeen patients walked along a 7-m walkway in both ankle-foot orthosis with dorsiflexion resistance and control (i.e., ankle-foot orthosis) conditions. Dorsiflexion resistance by spring and cam was set to increase linearly from zero-degree ankle dorsiflexion. Gait data were analyzed using a three-dimensional motion analysis system. FINDINGS: Ankle-foot orthosis with dorsiflexion resistance significantly increased the quasi-joint stiffness in the early and middle stance phase (P = 0.028 and 0.040). Furthermore, although ankle power generation in the ankle-foot orthosis with dorsiflexion resistance condition was significantly lower than in the control condition (P = 0.003), step length symmetry significantly increased in the ankle-foot orthosis with dorsiflexion resistance condition (P = 0.016). There was no significant difference in swing time ratio between conditions. INTERPRETATION: Applying dorsiflexion resistance in the paretic stance phase increased quasi-joint stiffness but did not lead to an increase in ankle power generation. On the other hand, applying dorsiflexion resistance also resulted in a more symmetrical step length, even though the ankle joint power generation on the paretic side did not increase as expected. Future research should explore whether modifying the magnitude and timing of dorsiflexion resistance, considering the biomechanical characteristics of each patients' ankle joint during gait, enhances ankle joint power generation.